Antimicrobial photodynamic therapy against clinical isolates of carbapenem-susceptible and carbapenem-resistant Acinetobacter baumannii.

Infections caused by Acinetobacter baumannii have become a challenge for healthcare professionals because of the rapid increase in Gram-negative bacteria resistant to carbapenem antibiotics. The objective of this study was to evaluate the effect of antimicrobial photodynamic therapy (aPDT) against different strains of A. baumannii isolated from patients with infectious process and hospitalized at the intensive care unit of the hospitals of São Jose dos Campos, São Paulo. These isolates were obtained from the Valeclin Clinical Analysis Laboratory (SP, Brazil) and were tested for susceptibility to the carbapenems imipenem and meropenem by determination of the minimal inhibitory concentration (MIC) using the broth microdilution method. The strains susceptible and resistant to these antibiotics were submitted to aPDT using methylene blue and a low-level laser with a wavelength of 660 nm and fluence of 39.5 J/cm2 (energy of 15 J and time of 428 s). The number of colony-forming units (CFU/mL) was analyzed by ANOVA and the Tukey test. The laboratory of origin of the clinical isolates identified 1.54% of 13,715 strains tested over a period of 8 months as A. baumannii. Among the A. baumannii isolates, 58% were resistant to carbapenems by the disk diffusion test. Susceptible isolates exhibited MIC of 0.5 to 1 µg/mL and resistant isolates of 64 to > 128 µg/mL. PDT reduced the number of A. baumannii cells for all isolates tested, with this reduction ranging from 63 to 88% for susceptible isolates and from 26 to 97% for resistant isolates. The percentage of viability was dependent on the strain analyzed. In conclusion, these data indicate that PDT could be an alternative strategy for the control of infections caused by carbapenem-resistant A. baumannii.

Antimicrobial activity of noncytotoxic concentrations of Salvia officinalis extract against bacterial and fungal species from the oral cavity.

The use of medicinal plants can be an alternative method for the control of microorganisms responsible for human infections. This study evaluated the antimicrobial activity of Salvia officinalis Linnaeus (sage) extract on clinical samples isolated from the oral cavity and reference strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata. In addition, testing assessed the cytotoxic effect of S officinalis on murine macrophages (RAW 264.7). Minimum inhibitory, minimum bactericidal, and minimum fungicidal concentrations of S officinalis extract were determined by broth microdilution method in 60 microbial samples. The cytotoxicity was checked by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The quantities of the proinflammatory cytokines interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) produced by RAW 264.7 were analyzed by an enzyme-linked immunosorbent assay. An S officinalis concentration of 50.0 mg/mL was effective against all microorganisms. Regarding cytotoxicity, the groups treated with 50.0-, 25.0-, and 12.5-mg/mL concentrations of S officinalis presented cell viability statistically similar to that of the control group, which was 100% viable. The production of IL-1ß and TNF-α was inhibited at a 50.0-mg/mL concentration of S officinalis. Thus, S officinalis extract presented antimicrobial activity on all isolates of Staphylococcus spp, S mutans, and Candida spp. No cytotoxic effect was observed, as demonstrated by the survival of RAW 264.7 and inhibition of IL-1ß and of TNF-α.

Thymus vulgaris L. extract has antimicrobial and anti-inflammatory effects in the absence of cytotoxicity and genotoxicity.

OBJECTIVES: This study evaluated the biological effects of the T. vulgaris L. extract., such as antimicrobial activity on planktonic cultures and mono- and polymicrobial biofilms, cytotoxicity, anti-inflammatory activity and genotoxicity. METHODS: Monomicrobial biofilms of Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans and Pseudomonas aeruginosa and polymicrobial biofilms composed by C. albicans with each bacterium were formed for 48h and exposed for 5min to the plant extract. Murine macrophages (RAW 264.7), human gingival fibroblasts (FMM-1), human breast carcinoma cells (MCF-7) and cervical carcinoma cells (HeLa) were also exposed to the plant extract for 5min and the cell viability were analyzed by MTT, neutral red (NR) and crystal violet (CV) assays. Interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) produced by RAW 264.7 was quantified by ELISA, after 24h exposure to the plant extract, both in the absence and presence of lipopolysaccharide (LPS) from Escherichia coli. Genotoxicity of the plant extract was evaluated by micronucleus formation (MN) in 1000 cells. The results were analyzed by T-Test or ANOVA and Tukey's Test (P≤0.05). RESULTS: All biofilms showed significant reductions in CFU/mL (colony-forming units per milliliter). Cell viability was above 50% for all cell lines. Anti-inflammatory effect on the synthesis of IL-1ß and TNF-α was observed. The MN was similar or lower than the control group in all cells. CONCLUSIONS: T. vulgaris L. extract was effective against all biofilms, promoted high cell viability, anti-inflammatory effect and presented no genotoxicity.

Biological activities of Rosmarinus officinalis L. (rosemary) extract as analyzed in microorganisms and cells.

R. officinalis L. is an aromatic plant commonly used as condiment and for medicinal purposes. Biological activities of its extract were evaluated in this study, as antimicrobial effect on mono- and polymicrobial biofilms, cytotoxicity, anti-inflammatory capacity, and genotoxicity. Monomicrobial biofilms of Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans and Pseudomonas aeruginosa and polymicrobial biofilms composed of C. albicans with each bacterium were formed in microplates during 48 h and exposed for 5 min to R. officinalis L. extract (200 mg/mL). Its cytotoxic effect was examined on murine macrophages (RAW 264.7), human gingival fibroblasts (FMM-1), human breast carcinoma cells (MCF-7), and cervical carcinoma cells (HeLa) after exposure to different concentrations of the extract, analyzed by MTT, neutral red (NR), and crystal violet (CV) assays. The anti-inflammatory activity was evaluated on RAW 264.7 non-stimulated or stimulated by lipopolysaccharide (LPS) from Escherichia coli and treated with different concentrations of the extract for 24 h. Interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) were quantified by ELISA. Genotoxicity was verified by the frequency of micronuclei (MN) at 1000 cells after exposure to concentrations of the extract for 24 h. Data were analyzed by T-Test or ANOVA and Tukey Test ( P ≤ 0.05). Thus, significant reductions in colony forming units per milliliter (CFU/mL) were observed in all biofilms. Regarding the cells, it was observed that concentrations ≤ 50 mg/mL provided cell viability of above 50%. Production of proinflammatory cytokines in the treated groups was similar or lower compared to the control group. The MN frequency in the groups exposed to extract was similar or less than the untreated group. It was shown that R. officinalis L. extract was effective on mono- and polymicrobial biofilms; it also provided cell viability of above 50% (at ≤ 50 mg/mL), showed anti-inflammatory effect, and was not genotoxic. Impact statement Rosmarinus officinalis L. extract effectively contributed to in vitro control of important species of microorganisms such as Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, and Pseudomonas aeruginosa in mono- and polymicrobial biofilms that are responsible for several infections in oral cavity as in other regions of the body. Furthermore, this extract promoted also cell viability above 50% at concentrations ≤ 50 mg/mL, excellent anti-inflammatory effect, showing inhibition or reduction of the synthesis of proinflammatory cytokines, being also non-genotoxic to cell lines studied. Thus, this extract may be a promising therapeutic agent that can be added in some medical and dental formulations such as toothpastes, mouthwashes, irrigating root canals, ointments, soaps, in order to control pathogenic microorganisms and biofilms, with anti-inflammatory effect and absence of cytotoxic and genotoxic.

Klebsiella pneumoniae Planktonic and Biofilm Reduction by Different Plant Extracts: In Vitro Study.

This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352). Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 107 UFC/mL of K. pneumoniae was distributed into 96-well microplates (n = 10) and after 48 h at 37°C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5%) were used to verify statistical significant reduction (p < 0.05) of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm.

Action of antimicrobial photodynamic therapy on heterotypic biofilm: Candida albicans and Bacillus atrophaeus.

The increase in survival and resistance of microorganisms organized in biofilms demonstrates the need for new studies to develop therapies able to break this barrier, such as photodynamic therapy, which is characterized as an alternative, effective, and non-invasive treatment. The objective was to evaluate in vitro the effect of antimicrobial photodynamic therapy on heterotypic biofilms of Candida albicans and Bacillus atrophaeus using rose bengal (12.5 µM) and light-emitting diode (LED) (532 nm and 16.2 J). We used standard strains of B. atrophaeus (ATCC 9372) and C. albicans (ATCC 18804). The biofilm was formed in the bottom of the plate for 48 h. For the photodynamic therapy (PDT) experimental groups, we added 100 µL of rose bengal with LED (P+L+), 100 µL of rose bengal without LED (P+L-), 100 µL of NaCl 0.9 % solution with LED (P-L+), and a control group without photosensitizer or LED (P-L-). The plates remained in agitation for 5 min (pre-irradiation) and were irradiated with LED for 3 min, and the biofilm was detached using an ultrasonic homogenizer for 30 s. Serial dilutions were plated in BHI agar and HiChrom agar and incubated at 37 °C/48 h. There was a reduction of 33.92 and 29.31 % of colony-forming units per milliliter (CFU/mL) for C. albicans and B. atrophaeus, respectively, from the control group to the group subjected to PDT. However, statistically significant differences were not observed among the P+L+, P+L-, P-L+, and P-L- groups. These results suggest that antimicrobial photodynamic therapy using rose bengal (12.5 µM) with a pre-irradiation period of 5 min and LED for 3 min was not enough to cause a significant reduction in the heterotypic biofilms of C. albicans and B. atrophaeus.

Different extracts of Zingiber officinale decrease Enterococcus faecalis infection in Galleria mellonella.

Dried, fresh and glycolic extracts of Zingiber officinale were obtained to evaluate the action against G. mellonella survival assay against Enterococcus faecalis infection. Eighty larvae were divided into: 1) E. faecalis suspension (control); 2) E. faecalis + fresh extract of Z. officinale (FEO); 3) E. faecalis + dried extract of Z. officinale (DEO); 4) E. faecalis + glycolic extract of Z. officinale (GEO); 5) Phosphate buffered saline (PBS). For control group, a 5 µL inoculum of standardized suspension (107 cells/mL) of E. faecalis (ATCC 29212) was injected into the last left proleg of each larva. For the treatment groups, after E. faecalis inoculation, the extracts were also injected, but into the last right proleg. The larvae were stored at 37 °C and the number of dead larvae was recorded daily for 168 h (7 days) to analyze the survival curve. The larvae were considered dead when they did not show any movement after touching. E. faecalis infection led to the death of 85% of the larvae after 168 h. Notwithstanding, in treatment groups with association of extracts, there was an increase in the survival rates of 50% (GEO), 61% (FEO) and 66% (DEO) of the larvae. In all treatment groups, the larvae exhibited a survival increase with statistically significant difference in relation to control group (p=0.0029). There were no statistically significant differences among treatment groups with different extracts (p=0.3859). It may be concluded that the tested extracts showed antimicrobial activity against E. faecalis infection by increasing the survival of Galleria mellonella larvae.

Essential oil of Melaleuca alternifolia for the treatment of oral candidiasis induced in an immunosuppressed mouse model.

BACKGROUND: The search for alternative therapies for oral candidiasis is a necessity and the use of medicinal plants seems to be one of the promising solutions. The objective of this study was to evaluate the in vitro and in vivo effects of the essential oil of Melaleuca alternifolia on Candida albicans. METHODS: The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of M. alternifolia were determined by the broth microdilution assay. For the in vivo study, twelve immunosuppressed mice with buccal candidiasis received topical applications of M. alternifolia with MBEC. After treatment, yeasts were recovered from the mice and quantified (CFU/mL). Mice were killed for morphologic analysis of the tongue dorsum by optical and scanning electron microscopy. Data were analyzed using Student's t test or Mann-Whitney test. RESULTS: The MIC of M. alternifolia was 0.195% and the MBEC was 12.5%. Treatment with M. alternifolia achieved a 5.33 log reduction in C. albicans and reduced the microscopic lesions of candidiasis. CONCLUSIONS: M. alternifolia oil at a 12.5% was effective to eradicate a C. albicans biofilm formed in vitro and to reduce yeasts of C. albicans in an immunosuppressed mouse model.

The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms.

The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multispecies biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. , the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

Control of microorganisms of oral health interest with Arctium lappa L. (burdock) extract non-cytotoxic to cell culture of macrophages (RAW 264.7).

OBJECTIVES: To evaluate the antimicrobial activity of Arctium lappa L. extract on Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Candida albicans, C. tropicalis and C. glabrata. In addition, the cytotoxicity of this extract was analyzed on macrophages (RAW 264.7). DESIGN: By broth microdilution method, different concentrations of the extract (250-0.4 mg/mL) were used in order to determine the minimum microbicidal concentration (MMC) in planktonic cultures and the most effective concentration was used on biofilms on discs made of acrylic resin. The cytotoxicity A. lappa L. extract MMC was evaluated on RAW 264.7 by MTT assay and the quantification of IL-1ß and TNF-α by ELISA. RESULTS: The most effective concentration was 250 mg/mL and also promoted significant reduction (log10) in the biofilms of S. aureus (0.438 ± 0.269), S. epidermidis (0.377 ± 0.298), S. mutans (0.244 ± 0.161) and C. albicans (0.746 ± 0.209). Cell viability was similar to 100%. The production of IL-1ß was similar to the control group (p>0.05) and there was inhibition of TNF-α (p<0.01). CONCLUSIONS: A. lappa L. extract was microbicidal for all the evaluated strains in planktonic cultures, microbiostatic for biofilms and not cytotoxic to the macrophages.

The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms

The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multi-species biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride (NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. Next, the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, and 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

Cytotoxicity of Brazilian plant extracts against oral microorganisms of interest to dentistry.

BACKGROUND: With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7). METHODS: Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1ß and TNF-α) using ELISA. RESULTS: In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1ß in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P. granatum L. (0.00 pg/mL) when compared to control (41.96 pg/mL). CONCLUSIONS: All plant extracts were effective against the microorganisms tested. The G. glabra L. extract exhibited least cytotoxicity and the E. arvense L. extract was the most cytotoxic.

In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals.

OBJECTIVE: The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals. MATERIAL AND METHODS: Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, G5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours. RESULTS: The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6. CONCLUSION: It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.

In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals

ABSTRACT Objective: The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals. Material and Methods: Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, G5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours. Results: The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6. Conclusion: It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity. .

Efeitos do suco de laranja e da molhabilidade da cerâmica sobre a formação do in situ / The effects of orange juice and ceramic wettability on in situ biofi lm formation

Este estudo procurou determinar os parâmetros do biofilme formado in situ, em cerâmica de revestimento, de acordo com a disponibilidade de carboidrato (suco de laranja) e a molhabilidade da superfície cerâmica. Discos de duas cerâmicas foram feitos (Vita VM7 e VM13, Vita Zahnfabrik, Bad Sackingen, Alemanha). Quatro discos foram aderidos a dispositivos palatais usados por oito voluntários. Colocou-se três gotas da água destilada (pH=6) ou suco de laranja (pH=3,5) sobre os discos oito vezes/dia. Após 48 horas in situ, os dois discos mais palatais foram removidos do dispositivo e analisados com microscopia confocal de varredura a laser (MCVL) para caracterização do biofilme (espessura média, μm e biovolume, μm3/μm2). O ângulo de contato (°) foi medido nas superfícies polidas de espécimes controle, e após 15 dias de uso nos espécimes da região frontal do dispositivo palatal. Os dados foram submetidos à estatística descritiva e inferencial (Mann-Whitney e teste t, p < 0,05). A molhabilidade de ambas as cerâmicas não diferiu estatisticamente. A formação do biofilme sobre as cerâmicas de revestimento não foi influenciada pelo suco de laranja ou pela molhabilidade da cerâmica...

This study aimed to determine the in situ biofilm parameters on veneering ceramics, according to the carbohydrate (orange juice) availability and the ceramic surface wettability. Disks were made out of two veneering ceramics (Vita VM7 and VM13, Vita Zahnfabrik, Bad Sackingen, Alemanha). Four disks were bonded to palatal devices worn by eight volunteers. The subjects dripped three drops of distilled water (pH=6) or orange juice (pH=3.5) on the disks 8x/day. After 48 h in situ, the two palatal disks were removed from the device and analyzed by Confocal Laser Scanning Microscopy (CLSM) for biofilm characterization (mean thickness, μm and biovolume, μm3/ μm2). The contact angle (°) was measured on the polished surfaces of as sintered specimens and after 15 day of in situ usage, on the frontal disks of the palatal device. The data were subjected to descriptive and inferential (Mann-Whitney and paired-t test, at p < 0.05) statistics. The biofi lm parameters of VM13 were not measurable, whereas the VM7 biofilm parameters were not signifi cantly affected by the type of liquid. The wettability of both ceramics also did not differ statistically. The biofi lm formation on the veneering ceramics was neither influenced by the orange juice dripping nor the ceramics’ wettability...

Antifungal effect of plant extracts on Candida albicans biofilm on acrylic resin / Efeito antifúngico de extratos vegetais sobre biofilme de Candida albicans em resina acrílica

Objetivo: Avaliar potencial antifúngico dos extratos de Equisetum arvense L. (cavalinha), Glycyrrhiza glabra L. (alcaçuz), Punica granatum L. (romã) e Stryphnodendron barbati-mam Mart. (barbatimão) sobre biofilme de Candida albicans em resina acrílica. Material e métodos: Cepa-padrão de C. albicans foi cultivada em ágar Sabouraud-dextrose por 24 h a 37°C. Após padronização do inóculo (106 células/mL) em espectrofotômetro, foram mantidos em caldo Brain Heart Infusion suplementado comsacarose (5%) um disco de resina acrílica estéril com 100 μL do inóculo padronizado, por 5 dias a 37 °C. As amostras dos grupos tratados (n = 10) foram expostas separadamente à concentração de 50 mg/mL de cada extrato por 5 min e ao antifúngico nistatina (48.83 UI/mL). Para o grupo não tratado (controle, n = 10) foi utilizada solução fisiológica estéril (NaCl 0,9%). Os biofilmes foram desagregados dos discos de resina acrílica por homogeneizador ultrassônico por 30 s. Após diluições decimais, foram feitas semeaduras em placas de Sabouraud-dextrose e incubação por 48 h a 37 ºC. Posteriormente, foram contadas as UFC/mL e os valores foram convertidos em log10 e realizada análise estatística (ANOVA e Tukey Test; p ≤ 0,05). Resultados: Todos os extratos naturais e a nistatina proporcionaram reduções significativas (p < 0,01) do biofilme de C. albicans em comparação ao grupo controle (NaCl 0,9%), no entanto, não houve diferença estatística entre os extratos (p = 0,1567). Conclusões: Houve formação de biofilme de C. albicans em resina acrílica e todos os extratos vegetais foram efetivos para esta levedura, atuando semelhantemente à nistatina.

Objective: Evaluating the antifungal potential of Equisetum arvense L. (horsetail), Glycyrrhiza glabra L. (licorice), Punica granatum L. (pomegranate) and Stryphnodendron barbatimam Mart. (barbatimão) extracts, after Candida albicans biofilm formation on acrylic resin. Material and methods: C. albicans standard strain was cultured on Sabourauddextrose agar for 24 h at 37 °C. After standardized in a spectrophotometer, 100 μL of the inoculums (106 cells/mL) and a sterile acrylic resin disc were maintained in Brain Heart Infusion broth supplemented with sucrose (5%), for 5 days at 37ºC. The samples of the treated groups (n = 10) were separately exposed to a concentration of 50 mg/mL of each extract for 5 minutes or to nystatin (48.83 IU/mL). For the untreated group (control, n = 10), it was used sterile saline (0.9% NaCl). Biofilms were disaggregated from the acrylic resin discs by an ultrasonic homogenizer for 30 s. After decimal dilutions, sowings in Sabouraud-dextrose plates were made with incubation for 48 h at 37°C. Later, CFU/mL was verified and the values were converted to log10 and they had their statistical analysis done (ANOVA and Tukey Test, p ≤ 0.05). Results: It was found that all plant extracts and nystatin resulted in significant reduction of C. albicans biofilm (p < 0.01) compared to the control group (0.9% NaCl). However, all of them showed similar reductions to each other (p = 0.1567). Conclusion: There was biofilm formation of C. albicans on acrylic resin and all plant extracts were effective against this yeast, acting similarly to nystatin.

Effect of Zingiber officinale and propolis on microorganisms and endotoxins in root canals

The purpose of this study was to evaluate the effectiveness of glycolic propolis (PRO) and ginger (GIN) extracts, calcium hydroxide (CH), chlorhexidine (CLX) gel and their combinations as ICMs (ICMs) against Candida albicans,Enterococcus faecalis, Escherichia coli and endotoxins in root canals. Material and Methods: After 28 days of contamination with microorganisms, the canals were instrumented and then divided according to the ICM: CH+saline; CLX, CH+CLX, PRO, PRO+CH; GIN; GIN+CH; saline. The antimicrobial activity and quantification of endotoxins by the chromogenic test of Limulus amebocyte lysate were evaluated after contamination and instrumentation at 14 days of ICM application and 7 days after ICM removal. Results and Conclusion: After analysis of results and application of the Kruskal-Wallis and Dunn statistical tests at 5% significance level, it was concluded that all ICMs were able to eliminate the microorganisms in the root canals and reduce their amount of endotoxins; however, CH was more effective in neutralizing endotoxins and less effective against C. albicans and E. faecalis, requiring the use of medication combinations to obtain higher success.

Efficacy of endodontic treatment for endotoxin reduction in primarily infected root canals and evaluation of cytotoxic effects.

INTRODUCTION: Endotoxins are one of the etiologic agents involved in the pathogenesis of apical periodontitis. The objectives of this clinical study were to investigate the effects of endodontic treatment by using different irrigants on endotoxins in root canals with pulp necrosis and apical periodontitis and to evaluate the cytotoxic effects. METHODS: Thirty-six root canals were selected. Samples were collected before (S1) and after instrumentation (S2). The root canals were divided into 3 groups (n = 12) according to the irrigant combination used: CLX + LW, 2% chlorhexidine gel + calcium hydroxide (0.14%, limewater); CLX + PmB, chlorhexidine + polymyxin B; CLX (control), chlorhexidine + saline. The third sampling (S3) was performed after ethylenediaminetetraacetic acid and S4 after intracanal medication (CLX + calcium hydroxide for 14 days). Endotoxins were quantified by the chromogenic Limulus amebocyte lysate assay, and cytotoxic effects were evaluated by the production of cytokines (interleukin-1ß, tumor necrosis factor α) in macrophages (RAW 264.7) stimulated with the root canal content. RESULTS: Endotoxins were detected in all root canals before instrumentation (S1). Group CLX + LW presented the greatest endotoxin reduction after instrumentation (99.18%), which was similar to group CLX + PmB (96.42%, P > .05) and different from group CLX (90.78%, P < .05). The intracanal medication promoted important endotoxin neutralization, with a reduction of 99.2% to 100%. The root canal content induced a higher production of tumor necrosis factor α and interleukin-1ß in S1 samples compared with samples obtained after treatment. CONCLUSIONS: The combination of CLX and limewater as irrigant was the most effective in reducing endotoxins in root canals, and intracanal medication was important to neutralize the cytotoxic effects.

Effectiveness of castor oil extract on Escherichia coli and its endotoxins in root canals.

This in vitro study sought to evaluate the effectiveness of castor oil extract used as an irrigating solution on Escherichia coli and its endotoxins in root canals. Sixty single-rooted teeth were prepared (using castor oil extract as irrigating solution) and divided into five groups (n = 12): Group 1 samples were treated with calcium hydroxide (Ca(OH)2), Group 2 samples were treated with polymyxin B, Group 3 samples were treated with Ca(OH)2 and 2% chlorhexidine gel (CHX), and Group 4 samples were treated with castor oil extract. A control group used physiological saline solution as an irrigant. Canal content samples were collected at four different times: immediately after instrumentation, seven days after instrumentation, after 14 days of intracanal medication, and seven days after removal of intracanal medication. A plating method was used to assess antimicrobial activity and the quantification of endotoxins was evaluated by the chromogenic Limulus lysate assay. Data were submitted to ANOVA and a Dunn test (a = 5%). Irrigation with castor oil extract decreased E. coli counts but had no effect on the level of endotoxins. Samples taken seven days after removal of medication revealed a significant reduction in endotoxin levels in Groups 3 and 4. Compared to the saline solution irrigation, castor oil extract decreased microorganism counts in root canals immediately after canal preparation. None of the medications used completely eliminated endotoxins in the root canal.

Efeitos clínicos e radiográficos do laser em baixa intensidade após a extração de terceiros molares inclusos / Clinical and radiographic effects of low intensity laser after extraction of unerupted third molars

Introdução: O laser em baixa intensidade tem sido indicado como tratamento coadjuvante no pós-operatório da cirurgia de extração dentária. Objetivo: O objetivo deste trabalho foi avaliar os efeitos clínicos e radiográficos do laser em baixa intensidade na cirurgia de exodontia de terceiros molares inclusos. Material e método: Oito pacientes foram submetidos à extração dos terceiros molares inferiores inclusos. O dente esquerdo foi tratado com laser durante a cirurgia e por mais dois dias do pós-operatório (Grupo Laser). A cirurgia do dente direito foi realizada após 15 dias da cirurgia do dente esquerdo e não recebeu laserterapia (Grupo Controle). A avaliação clínica do pós-operatório foi baseada na medida do edema e na análise de questionário para avaliação da dor. Após 40 dias de cada cirurgia, foram feitas radiografias periapicais digitais para medida das densidades ópticas da reparação óssea, por meio do programa Image J. Os dados obtidos na medida do edema e na análise de densidade óptica foram submetidos ao teste estatístico t de Student. Resultado: O nível de dor dos pacientes no pós-operatório foi menor no Grupo Laser em relação ao Grupo Controle. Entretanto, na medida do edema e na análise de densidade óptica das radiografias, não houve diferença estaticamente significante do Grupo Laser em relação ao Grupo Controle. Conclusão: De acordo com os parâmetros utilizados neste estudo, concluiu-se que a aplicação do laser em baixa intensidade promoveu analgesia no pós-operatório, porém não teve efeito sobre o edema e a reparação óssea.

Introduction: The low intensity laser therapy (LLLT) has been indicated as coadjuvant treatment of postoperative dental extraction surgery. Objective: The aim of this study was to evaluate the clinical and radiological findings of LLLT in the surgery for extraction of unerupted third molars. Material and method: Eight patients were submitted to extraction of mandibular third molar. The left tooth was treated with laser during surgery and for another 2 days after surgery (Laser Group). The right tooth surgery was performed after 15 days and did not receive laser therapy (control group). Clinical evaluation of the postoperative period was based on the measuring of edema and analysis of a questionnaire to assess pain. After 40 days of each surgery, digital periapical radiographs were made and measured the optical density of bone repair were analyzed using the Image J. The data obtained in the measurement of edema and analysis of optical density were tested using Student t test. Result: The level of pain in postoperative patients was lower in the laser group compared to the control group. However, in the measurement of edema and analysis of optical density of radiographs there was no statistically significant difference in the laser group compared to control. Conclusion: According to the parameters used in this study, we can concluded that the application of LLLT promoted analgesia postoperatively, but did not show effects on edema and bone repair.